Prediction of Brake Moan Noise Using CAE Techniques 2021-01-0811

Brake moan noise is a friction induced phenomenon occurring at very low brake pressure, speeds and in the frequency range of 100-500 Hz. Moan noise is induced due to stick-slip phenomenon between brake rotor and pad. In this paper, prediction of moan noise with complex eigenvalue method along with other static steps is described. The complex eigenvalue is performed in multiple steps of analysis. Pretension analysis followed by nonlinear static analysis (For brake pressure and rotor velocity) is performed to provide a sliding motion between the pads and the disk. From the pre-stressed condition at the end of the static analysis, the tangent stiffness matrix is found out by linear perturbation method and followed by that complex eigenvalue analysis also performed. From the eigenvalue analysis, instability modes and the corresponding mode shapes of the brake assembly are calculated by considering the nonlinear effect of loading and contacts. The stiffness of the suspension parts is one of the critical elements in the contribution of the moan noise. This paper attempts to improve the percentage of correlation by capturing stiffness of the suspension part in an appropriate manner and a close correlation is achieved between finite element analysis and test results with minimal deviation. In the brake moan noise simulation, component contribution factor (CCF) is also calculated as an output parameter to find out the major contributing parts at the instability frequency. A comprehensive study is performed for evaluating the brake instability frequencies due to the change in the friction coefficient and the brake pressure.